Title :
Metastable dynamical regimes in an oscillatory network modulated by an agent´s sensorimotor loop
Author :
Santos, Bruno A. ; Barandiaran, Xabier E. ; Husbands, Phil
Author_Institution :
CCNR, Univ. of Sussex, Brighton, UK
Abstract :
The last two decades have witnessed an increasing focus on oscillatory brain dynamics as a means of understanding a variety of cognitive phenomena. Most theoretical and mathematical approaches in this area have mainly worked under two assumptions: a) that the most significant aspect of oscillatory brain dynamics is synchronization; and, b) that most part of functional brain dynamics can be understood without incorporating the sensorimotor loop into the picture. Although significant progress has been achieved with these assumptions, we believe they might limit future development of dynamical approaches to brain functioning and cognitive behaviour. Looking at the whole picture of brain dynamics, rather than only moments of synchronization, and analysing it inside the sensorimotor loop can provide new insights on how the brain operates. In this paper we present a robotic agent capable of performing phototaxis controlled by a Kuramoto-model based oscillatory neural network. The network parameters were optimized using a genetic algorithm. The resulting brain and behavioural dynamics are analysed within Kelso´s Coordination dynamic framework. We found that: a) during a whole behavioural episode of phototaxis the robot´s brain undergoes different metastable dynamical regimes of phase-lock and phase-scattering, represented by the relative phase and phase coherence among oscillators; b) even for a simple task, metastable coordination patterns and functional behaviour emerges without the need for a specific synchronization signature; and, c) sensorimotor loop dynamics plays a critical role generating and sustaining functional metastable regimes of brain activity by modulating the network´s control parameter.
Keywords :
brain; cognitive systems; genetic algorithms; neural nets; robots; sensors; Kuramoto-model based oscillatory neural network; cognitive behaviour; coordination dynamic framework; genetic algorithm; metastable coordination pattern; metastable dynamical regime; oscillatory brain dynamics; robotic agent; sensorimotor loop; synchronization; Brain models; Couplings; Genetic algorithms; Oscillators; Robot sensing systems; Synchronization;
Conference_Titel :
Artificial Life (ALIFE), 2011 IEEE Symposium on
Conference_Location :
Paris
Print_ISBN :
978-1-61284-062-8
DOI :
10.1109/ALIFE.2011.5954659